1. Field of the Invention
The present invention relates to an optical fiber component for connecting efficiently and correctly between optical components, between optical boards, and between optical racks using optical fibers.
2. Description of the Related Art
Various types have so far been proposed for optical fiber components for connection (hereinafter referred to also as an optical fiber wiring board) connecting between optical components, between optical boards, and between racks. Optical fiber wiring boards, in which optical fibers are arranged on a substrate, such as a flexible resin film, according to predesigned patterns are mainly used. Moreover, as optical fiber wiring boards, on which optical fibers are laid and then fixed, those having structures as a sandwiched type in which optical fibers are sandwiched between substrates or between films, and an embedded type in which optical fibers arranged on a substrate are embedded in a thermoplastic resin have been proposed.
The above described sandwiched type optical fiber wiring board has the following problem: when the wiring board is bent, since a force is exerted in a direction to shrink a substrate or a film in the inside of the bent portion and a force is exerted in a direction to elongate it in the outside, the substrate or film sandwiching optical fibers has lager resistance to bending, and the wiring board is thus hard to be bent. Moreover, in an optical fiber wiring of a sandwiched type, upon such bending, a stress is also exerted on optical fibers which was attributable to an increase in optical loss.
For the above described embedding type optical fiber wiring board, optical fibers are fixed by curing a thermoplastic resin. A problem occurred that a stress was given to the optical fibers at the time of this curing process. Furthermore, there were such disadvantages that transmitted light intensity easily varied according to changes in temperature and flexibility to bending of a wiring board was insufficient. Moreover, some thermoplastic resins used in the embedding type optical fiber wiring board have weak mechanical strength, and there is a need for improving such mechanical characteristics. In addition, when an embedding type optical fiber wiring board has a structure in which optical fibers are completely embedded, weight of a resin itself becomes large (for example, an optical fiber wiring board with a size of 210 mm×297 mm (A4-size) and a thickness of 2 mm may weigh about 120 g), and it is therefore required to consider a stopper for supporting the weight and prevention of bending by self-weight.
In addition, an optical fiber wiring board might be used for wiring in a limited space and is also assumed to be installed in the state of being bent at the time of mounting. Therefore, an increase in optical loss and a decrease in flexibility upon bending pose a big problem. Moreover, in wiring between boards, an optical fiber wiring board is installed on the outside of a rack containing the optical board to connect the boards, and therefore, the optical fiber wiring board is also assumed to be accidentally hooked or pushed during work. In such a case, a poor mechanical property poses a problem. Moreover, when a large-scaled optical fiber wiring board for wiring between racks or wiring between boards is manufactured using embedding type optical fiber wiring boards, the wiring board becomes heavy to cause problems in mounting.
These problems are important and must be solved in the optical characteristics, reliability, and mounting property of an optical fiber wiring board. However, none of optical fiber wiring boards so far proposed has realized an optical fiber wiring board in which special measures are taken for solving these problems.